Many industrial processes produce fluid waste streams which may contain water and bio- and non-biodegradable components. The non-biodegradable components could be environmentally hazardous materials, such as acids, chlorinated solvents a.o. Commonly, these fluid waste streams are incinerated in a fixed or rotary furnace. The resulting flue gas from burning these streams is usually treated to remove pollutants, such as CO, SO.sub.2, and/or Cl.sub.2. Carbon monoxide, for example, can be oxidized to form CO.sub.2 while Cl.sub.2 and SO.sub.2 can be chemically removed, i.e., by reacting them with alkali or alkaline materials. Filtering means may also be used to remove dust if it is present in the flue gas.
It has been known to employ air/fuel burners in a furnace to incinerate fluid waste streams. The air/fuel burners, however, are generally inefficient in burning fluid waste. Much time may be necessary to evaporate water, if present, and then burn the bio- and non-biodegradable components, thereby limiting a rate at which the fluid waste streams are introduced into a furnace for incineration. This problem is compounded by a high volume of a flue gas which usually results from employing air/fuel burners in incinerating the fluid waste. As the volume of a flue gas increases, the throughput of a furnace is decreased. The term "throughput" is defined as "a rate at which a liquid waste stream is fed to a furnace for incineration".
To enhance the throughput of a furnace, the use of oxygen enriched air or lancing pure oxygen in or under the air flame, has been employed. These oxygen techniques, however, are believed to have a number of disadvantages. One of the common disadvantages of pure oxygen lancing includes a partial mixing of the oxygen with the air flame leading to less than the expected increased throughput and to an eventual uncontrollable flame front which could cause possible overheating of downstream filter equipment. Another disadvantage of higher oxygen enrichment levels of the combustion air, is the possible overheating of the furnace refractory in the vicinity of the air flame area.
Therefore, there is a need to find a means by which a throughput rate can be increased without creating unstable and uncontrolled flames and temperature conditions, which could be deleterious to a fluid waste furnace or a liquid waste incinerator and its subsequent communicating off-gas cleaning system.